Door latch with notched cam



May 13,1969 K. H. WOLVERTON 3,443,407

DOOR LATCH WITH NOTQHED CAM Filed Aug. 22, 1967 INVENTOR United States Patent 3,443,407 DOOR LATCH WITH NOTCHED CAM Kenneth H. Wolverton, Moline, Ill., assignor to Ametek, Inc., New York, N.Y., a corporation of Delaware Filed Aug. 22, 1967, Ser. No. 662,467 Int. Cl. D0615 37/28, 37/42 US. Cl. 68-143 7 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a door interlock arrangement for the casing door of a washer-extractor and more particularly to a mechanical interlock whereby the casing door may be opened only when one of the pockets within the drum is aligned with the casing door.

A conventional form of washer-extractor or washer particularly intended for commercial or institutional use comprises a stationary casing with a rotatable drum therein. The casing is provided with a door to permit access to the drum therein into which the laundry is placed. The drum may have longitudinally extending partitions therein so as to divide the drum into a plurality of longitudinally extending pockets. The partitions are radially disposed within the drum so that the cross sectional shape of a pocket is that of a sector of a circle. In certain applications, it is particularly desirable that the casing access door be located at the end of the casing. Thus, the operator has access to the ends of the drum pockets. The ends of the drum pockets are generally provided with doors or openings therein. In such washer-extractors, however, the problem arises in aligning the individual drum doors with the casing door when the rotation of the drum is stopped. It frequently occurs that the casing door is opened by the operator but that the drum door is not accessible. Consequently, the operator must carefully move the drum to such a position that the particular pocket opening is aligned with the cylinder door.

An object of the present invention is to provide an improved door interlock for the door of a casing of a washerextractor with a multi-pocket rotatable drum therein.

Another object of the invention is to provide a door interlock for the casing of a washer-extractor whereby the door can only be opened when a drum opening is aligned with the casing door.

A further object of the invention is to provide a simple yet effective door interlock construction for the casing door of a washer-extractor.

The door interlock according to the present invention may be incorporated in a washer-extractor or washer having a stationary casing with a rotatable drum therein, the drum having a plurality of longitudinally extending pockets. There is a door at one end of the casing for access to the drum pockets. In one aspect of the invention, the door interlock may comprise a pivotally mounted crank-shaped latch with a latch bar mounted on one arm of the latch. A spring acts upon the latch to urge the latch bar into the path of the door to block opening of the door. A handle extends from the other arm of the latch for selectively pivoting the latch. A notched disk may be mounted on the end of the drum shaft for rotation therewith. The notches in the periphery of the disk may be V-shaped and correspond to the positions of the pockets "ice bar of the latch may be pivoted into a notch and out of the path of the door when a drum pocket is aligned with the casing door. Otherwise, the latch bar rides on the periphery of the notched disk and remains in the path of the casing door. A cover may enclose the disk, latch and spring, the cover having openings so that the latch bar and handle may project therethrough.

The spring may be so positioned with respect to the latch that the latch is held in whatever position it has been moved by manipulation of the handle.

Other objects, advantages and features of the invention will become apparent from the following description and accompanying drawings, which are merely exemplary.

In the drawings:

FIG. 1 is an end elevational view of a washer-extractor showing the casing door and the mounting of the door interlock of the present invention;

FIG. 2 is a front elevational view showing the end thereof illustrated in FIG. 1;

FIG. 3 is a vertical sectional view through a portion of the end of the washer-extractor illustrated in FIG. 2 and in enlarged scale to illustrate the mounting of the disk on the drum shaft;

FIG. 4 is an elevational view of the door interlock arrangement with a portion of the cover therefor removed; and

FIG. 5 is an overall perspective view of the latch of the door interlock.

Referring to the drawings wherein like reference symbols indicate the same parts throughout the various views, a specific embodiment of the invention will be described in detail.

In FIG. 1 there is indicated generally at 10 a washer-e tractor which has a stationary casing 11 and a drum 12 rotatably mounted therein. The drum 12 is mounted on a shaft 13 journaled at 14, as may be seen in FIG. 3. One end of the casing is indicated at 15 and has an access door 16 with a handle 17 which may be locked in the closed position.

The door interlock is indicated generally at 18 and is enclosed in a cover 19 mounted on a supporting shelf 20 attached to casing end 15. The interlock is illustrated in detail in FIGS. 4 and 5 and comprises a crank-shaped latch 21 pivotally mounted at 22 and having arms 23 and 24. A latch bar 25 having a V-shaped edge 26 is mounted on latch arm 23, as may be seen in FIG. 5. The latch bar 25 projects upwardly through a cover opening 27 to block the casing door from opening in a manner to be presently described.

A handle 28 is mounted on latch arm 24 and projects outwardly of cover 19 through a slot 29. A thrust plate 30 mounted on the lower portion of latch arm 24 is acted upon by a spring 31 mounted on a base plate 32 within the interlock cover 19.

A disk 33 having V-shaped notches 34 in its periphery is mounted by means of bolts 35 to the end of drum shaft 13.

In its normal or blocking position, as illustrated in the solid lines in FIG. 4, an edge 36 of the latch bar engages a bracket arm 37 which is mounted on the casing door 16. As may be seen in FIG. 3, in this position the door is prevented from opening.

The V-shaped notches 34 correspond in position to the longitudinally extending pockets formed within the drum by radial partitions. In the present embodiment, the drum is provided with two partitions and, accordingly, the disk 33 is provided with two diametrically opposed V-shaped notches 34. Where the drum is provided with three pockets, there will be three equally spaced notches in the periphery of disk 33. The notches are so positioned in the disk 33 that a notch is immediately below latch bar 25 when a drum pocket or pocket door is aligned with the casing door 16.

When the drum is stopped from rotating and the drum pocket is properly aligned with the casing door, a notch 34 will be aligned with the latch bar. The latch handle 28 is then moved upwardly to the position shown in dashed lines in FIG. 4 and the latch bar is moved downwardly out of the path of door bracket arm 37. The casing door can now be opened. When the door is open, .a door switch opens the control circuit to prevent accidental starting of the drum. After the casing door has been closed and the drum cylinder rotated a few degrees, the latch assembly returns to its original position as illustrated in FIG. 4. The dimensions of the door, V-shaped notches, latch bar knife edge and the speed of rotation of the drum during the washing operation are such that the door cannot be opened while the drum is rotating.

The spring 31 is positoned so as to maintain the latch in either its blocking or unblocking position.

Thus, it can be seen that the present invention discloses a simple yet effective interlock for the casing door of a washer-extractor whereby the casing door is prevented from opening until a door on the end of the drum rotating therein is aligned with the casing door. When the drum door is properly aligned, the interlock can be manually moved to the unblocked position and the casing door opened. When the casing door is closed, rotation of the drum will automaitcally return the interlock to the blocking position by the cam action of the V-shaped notch against the V edge of the latch bar. The position of the V-shaped disk is responsive to the position of the drum. While the present embodiment discloses the disk as fastened on the end of the drum shaft, the disk may be operatively connected to the drum shaft in any other desired manner.

It is to be understood that changes can be made in various details of construction and arrangement of parts without departing from the spirit of the invention, except as defined in the appended claims.

What is claimed is:

1. In a washer-extractor having a stationary casing with a rotatable drum therein and said drum having a plurality of longitudinally extending pockets, there being a door at one end of the casing for access to the drum pockets; a door interlock comprising a pivotally mounted latch having a latch bar thereon, a spring acting upon said latch to urge said latch bar into the path of the door to block opening of the door, a handle on said latch for pivoting the same, and a disk operatively connected to said drum for rotation therewith, there being notches in the periphery of said disk corresponding to the pockets in the drum and positioned such that a notch receives said latch bar when a drum pocket is lined up with said casing door whereby the latch may be pivoted to move the latch bar from blocking the door.

2. In a washer-extractor as claimed in claim 1 wherein said disk is mounted on the end of a drum shaft.

3. In a washer-extractor as claimed in claim 1 wherein said drum has two pockets and'said disk has two diametrically opposed notches.

4. In a washer-extractor as claimed in claim 1 wherein said notches are V-shaped.

5. In a washer-extractor as claimed in claim 1 wherein said latch is a crank and said latch bar is mounted on one arm thereof.

6. In a washer-extractor as claimed in claim 5 wherein said handle is mounted on the other arm of said latch.

7. In a washer-extractor as claimed in claim 1, further comprising a cover enclosing said disk, latch and spring, and having openings therein for the projection therethrough of said latch bar and handle.

References Cited UNITED STATES PATENTS 1,085,406 1/1914 Daniels 68-139 2,267,671 12/1941 Shearer 68-139 2,346,648 4/ 1944 Berry 68-139 X 2,571,197 10/1951 Buss 68-143 2,579,761 12/ 1 Schmidtke 68-139 2,921,710 1/1960 Hutterer 68-143 X 3,158,707 11/1964 Files 68-143 X 3,243,977 4/1966 Norgaard 68-139 WALTER A. SCHEEL, Primary Examiner.

J. M. NEARY, Assistant Examiner.

T UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. LMILH Y Dated May 13 1969 Invent0r(8) Kenneth H. wolvorton It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

F Column 2, insert before line I, -1'n the drum. The 1 notches are so positioned that the Iatch--.

SIGNED AND SEALED oc'r 211969 snm Attest:

Ed ard M. Ficlchcr, 5 Irmu E- W. m. Amfing Omar M35101: at Paton 

